Full-scale Activated Sludge Wastewater Research Articles

Plant-wide modelling and simulation using steady-state data: a case study of the Gliwice WWTP, Poland

In last decade the focal point of the activated sludge (AS) modelling shifted from a secondary-treatment to a plant-wide level. This new approach offers more possibilities, therefore demands more effort and expertise from a modeller. This paper presents a plant-wide approach to modelling and simulation of a full-scale AS wastewater treatment plant (WWTP). The construction and routine operational data of the full-scale Central WWTP in Gliwice (Poland) were used in this study to develop an integrated model of the water and sludge lines of the plant. The core of the plant model was the Activated Sludge Model No.1 (ASM1), which combined with sub-models of the other processes, was implemented in the WEST® Software version 3.7.6. The calibration strategy, verification and predictive capacity of the model are discussed. The calibrated model permitted acceptable accuracy of the simulation, yet limited data restrained its scope. Thus, the obtained mathematical description of the plant is a preliminary yet sound basis for a more versatile model. The model limitations and opportunities for its further applications and development are discussed.

Rain events and their effect on effluent quality studied at a full scale activated sludge treatment plant

The effect of rain events on effluent quality dynamics was studied at a full scale activated sludge wastewater treatment plant which has a process solution incorporating pre-denitrification in activated sludge with post-nitrification in trickling filters. The incoming wastewater flow varies significantly due to a combined sewer system. Changed flow conditions have an impact on the whole treatment process since the recirculation to the trickling filters is set by the hydraulic limitations of the secondary settlers. Apart from causing different hydraulic conditions in the plant, increased flow due to rain or snow-melting, changes the properties of the incoming wastewater which affects process performance and effluent quality, especially the particle removal efficiency. A comprehensive set of on-line and laboratory data were collected and analysed to assess the impact of rain events on the plant performance.